Water preparation for watering hemp

In caring for cannabis, it is important not only to have enough water for irrigation, but also its purity. Ordinary tap water or well water is not clean enough to irrigate. It contains dissolved gases, chlorine, cations, anions and particulate matter.

Water quality is assessed according to three criteria:

Acidity – pH;
Organoleptic properties.
Acidity – pH

The acidity of water determines the ratio of hydrogen and hydroxyl ions in it. If positive hydrogen ions predominate in the solution, then it will be an acidic environment. Its value is measured from 1 to 6.9. If the solution contains more negative hydroxyl ions, then it will be alkali. Its value is measured from 7.1 to 14. Pure water maintains a balance between positive and negative ions, and therefore has a neutral pH level (pH = 7).

The pH level affects a plant’s ability to absorb nutrients and minerals that are essential for healthy growth and development. All plant species have their own optimal pH value, at which they properly absorb the substances they need.

The optimum pH of the water for irrigating hemp is 5.5-6.5.

Water hardness is an indicator of the quantitative value of the presence of calcium and magnesium ions in water. It is measured in milligram equivalent per liter (meq / L). The increased level of calcium ions in the irrigation water interferes with the absorption of important nutrients by the plant. A clear sign of using too hard water is the formation of a white crust on the surface of the soil.

The most hardness is considered to be water from wells, which contains many impurities. Its hardness index is usually 8-10 meq / l. A relatively low hardness is considered to be an indicator of 3-6 mg-eq / l. The softest water is rain or melt water, but not in industrial areas. Its rigidity is close to zero.

For watering marijuana, it is advisable to use water, the hardness of which will be less than 3 mEq / L, but values ​​of 3-4 mEq / L are acceptable.

Organoleptic properties

Clarity is the most obvious indicator of water purity. It depends on the amount of mechanical or chemical particles in the liquid. The less impurities in the water, the cleaner it is. The cleaner the water, the more transparent it is.
Colour. Water is inherently colorless. If it has any shade, then this indicates the content of impurities in it. Yellow color indicates the content of iron salts and decomposition products of vegetation in the water, green indicates the presence of microalgae.
Smell. One of the features of clean water is odorless. Any odor indicates that biodegradation products or chemicals are present in the water. If you use tap water to irrigate cannabis, you can clearly smell chlorine, making it unacceptable for watering. And having felt the smell of hydrogen sulfide, we can say that the water contains pathogenic microorganisms.
Taste. The taste of irrigation water does not play any role, but by the presence of foreign tastes, one can judge the presence of impurities in the water.
Temperature. Any plants, including hemp, are watered only with water at room temperature. Low or high water temperatures can damage the roots of the plant, which will negatively affect its life. You cannot water the hemp with boiled water, because when boiling, oxygen evaporates from it, which is important for the normal functioning of the root system.

Water treatment methods for watering hemp


It is the simplest, fastest and most free option. It is enough to collect water in a container of a suitable volume, and let it settle for about 1-2 days. At the same time, chlorine, which is necessarily present in the water supply system, will evaporate from it, and all heavy impurities will settle.


Cannabis water can be purified using ion exchange or osmotic filters. But water filtration takes a very long time, especially with large volumes and low quality of filtered water. It also implies financial costs, because the filters must be changed regularly. But the filtration method allows you to almost completely purify water from impurities and soften it.


The freezing method gives a positive result only if it is carried out correctly. Pure water begins to turn into ice at a temperature of 0 degrees, and water with an admixture already at negative temperatures. Therefore, when the sub-zero temperature is reached, all unfrozen water is drained, since it is this water that contains impurities. And the remaining ice is turned into melted soft water.

Peat addition

Getting into water, peat acidifies it, absorbs heavy metals and saturates it with humic acids. In this case, the color of the water becomes yellowish. Peat is poured into a bag that allows water to pass through, after which it is immersed in water for several days. It is required to immerse about 100 g of peat in 10 liters of water.

Adding acid

With increased hardness of the water used or increased alkalinity of the soil, citric or oxalic acid can be added to the water. Thus, the acidity rises and the pH level stabilizes. Add 2 g of oxalic acid to 10 l of water. The exact amount of acid required can be calculated by measuring the pH of the water by adding acid gradually.